2.1 Project Team

RCI Project Team experts in the fields of fire behavior and suppression, geographic information systems (GIS), natural resource ecology, and forest health collaborated to complete a Community Risk/Hazard Assessment for each community. Each Project Team included a Fire Specialist with extensive wildland fire prevention and suppression experience in Nevada and a Resource Specialist experienced in the natural resource environment of the Great Basin.

The Project Teams used standardized procedures developed from the Draft Community Wildland Fire Assessment For Existing and Planned Wildland Residential Interface Developments in Nevada during the assessment process (Nevada’s Wildland Fire Agencies, Board of Fire Directors, April 2001; revised 2002). This approach incorporates values for fuel hazards, structural hazards, community preparedness, and fire protection capabilities into an overall community rating. A glossary of wildland fire terms is included in Appendix A.

2.2 Base Map Data Collection

The project geographic information system (GIS) specialists compiled and reviewed statewide geospatial data and provided the assessment teams with maps for use and verification in the field. Data sources for the maps were the Nevada Fire Safe Council, the Nevada Department of Transportation, the Natural Resource Conservation Service, the Forest Service, and the BLM. Data includes:

Spatial Dataset	Data Source
Land ownership	BLM Nevada State Office Mapping Services
Vegetation communities	Nevada Gap Analysis Program Data, Utah Cooperative Fish and Wildlife Research Unit, Utah State University
Topography	USGS Digital Elevation Models and Topographic Maps
Fire suppression resources	Field Interviews
Roads	“TIGER” Census data 2000
Current aerial photographs	US Geologic Survey Digital Orthophoto Quadrangles (1994, 1996, or 1998)
Fuel types	BLM Utah State Office Fire Hazard Potential Data
Fire History	BLM Nevada State Office Mapping Services USFS Nevada State Office

Existing data was reviewed and the pertinent information was compiled on maps in GIS format. The Project Teams verified the GIS data during field assessments. The GIS specialist provided the data management for quality assurance and accuracy analysis of the statewide geospatial data and map production.

2.2.1 Wildfire History

Wildfire history information was mapped using BLM and USFS datasets and GIS databases that identify wildfire perimeters on federally managed lands covering the past 24 years. Fire perimeters were mapped by agency personnel using Global Positioning System (GPS) and screen digitizing on source maps with a minimum detail level of 1:250,000. This dataset was updated at the BLM Nevada State Office at the end of each fire season from information provided by each Nevada BLM Field Office. The dataset is the central source of historical GIS fire data used for fire management and land use planning on federal lands.

The Project Team Fire Specialists identified additional fire perimeters not present in the BLM and USFS datasets as a result of interviews with local fire experts. Fires that occur on private lands are generally recorded on paper maps and have not been consistently included in the federal agency GIS datasets. Additional fire locations identified during the interviews were recorded on the field maps where possible and added to the project wildfire perimeter dataset.

In addition to the fire perimeter information, point data for all fire ignitions within Nevada from 1980 to 2003 were obtained from the National Interagency Fire Center (NIFC) database in Boise, Idaho. This dataset includes an ignition point coordinate and an acreage component as reported to NIFC through a variety of agencies. This data is summarized in Table 3-2 and provides the ignition point locations for the maps in this report. In many cases, the ignition point location is only accurate to the section; in such cases, the point coordinate is located in the section center on the maps.

The wildfire history and ignition history data were used to formulate risk ratings and to develop recommendations specific to areas that have been repeatedly impacted by wildland fires. Observations made from the RCI Project Team Fire Specialists and comments from local fire agencies were used to develop recommendations in areas without recent wildfire activity where accumulations of fuels or expansion of urban development into the interface area represents a growing risk.

2.3 Community Risk/Hazard Assessment

The wildland-urban interface is the place where homes and wildland meet. This project focuses on identifying risks and hazards in the wildland-urban interface areas by assessing each community individually. Site-specific information for each community was collected during field visits conducted March 1 through 3, 2004. The predominant conditions recorded during these site visits were used as the basis for the Community Risk/Hazard Assessment ratings.

2.3.1 Ignition Risk Assessment Criteria

The Project Team Fire Specialists assigned an ignition risk rating of low, moderate, or high to each community assessed. This rating is based on interpretation of the historical record of ignition patterns and fire polygons provided by NIFC, BLM, and USFS databases, interviews with local fire department personnel and regional Fire Management Officers, field visits to each community, and the professional judgment of the fire specialists based on their experience with wildfire ignitions in Nevada.

2.3.2 Hazard Assessment Criteria

The Community Risk/Hazard Assessments were completed using methodology outlined in the Draft Community Wildland Fire Assessment: For Existing Wildland Residential Interface Developments in Nevada (Nevada’s Wildland Fire Agencies 2001; revised 2002). This system assigns community hazard and risk values low through extreme based on the following scoring system:

Category	Score
Low Hazard	< 41
Moderate Hazard	41-60
High Hazard	61-75
Extreme Hazard	76+

To arrive at a score for the community, five primary factors that affect potential fire hazard are assessed: community design, structure survivability, defensible space, availability and capability of fire suppression resources, and physical conditions such as fuel loading and topography. A description of each of these factors and their importance in developing the overall score for the community is provided below. Individual community score sheets presenting the point values assigned to each factor in the hazard assessment score are provided at the end of each community section. Tables presenting the point values assigned to each element in the hazard assessment are provided for each community at the end of its respective section.

Community Design

Community design accounts for 26 percent of the total assessment score. Many aspects of community design can be modified to make a community more fire safe. Factors considered include:

• Interface Condition Community safety is affected by the density and distribution of structures with respect to the surrounding wildland environment. Four condition classes are used to categorize the wildland-urban interface: Classic, Intermix, Occluded, and Rural. Definitions for each Condition Class are defined in the glossary of wildland terms in Appendix A.
• Access. Design aspects of roadways influence the hazard rating assigned to a community. The presence of secondary entrances and exits and loop roads in a community improves evacuation and access. Roads less than twenty feet in width often impede two-way movement of vehicles and fire suppression equipment. A road gradient of greater than five percent can imply increased response times for vehicles carrying water. Hairpin turns and cul-de-sacs with radii of less than 45 feet can cause problems for equipment mobility. Fire-resistant street signs consistently placed at neighborhood intersections and easily visible house addresses help to lower the hazard rating of a community.
• Utilities. The condition of electric utilities and the maintenance of vegetation within the power line corridor accounts for four percent of the overall hazard total. It is important to keep power line corridors clear of flammable vegetation, especially around power poles. In the event of a wildfire, flames from excessive fuels in the electric utility corridor can be of sufficient length and intensity to damage power lines, transformers, and the power poles that support them. Damage to this infrastructure during a wildfire event commonly causes power failures. Proper vegetation maintenance in power line corridors also reduces the risk of additional ignitions, as fires have been known to start from arcing power lines and transformers during windy conditions.

Construction Materials

Construction materials account for sixteen percent of the total score for the risk and hazard assessment. While it is not feasible to expect all structures in the wildland-urban interface area to be rebuilt with non-combustible materials, there are steps that can be taken to address specific elements that affect the potential for structure ignition in the interface area. Construction factors considered in the assessment include:

• Structure Building Materials. The composition of building materials determines the length of time a structure could withstand high temperatures before ignition occurs. Houses composed of wood siding and wood shake roofing are usually the most susceptible to ignitions. Houses built with stucco exteriors and tile, metal, or composition roofing are able to withstand much higher temperatures and longer heat durations and, thereby, present a much lower ignition risk from firebrands or the radiant heat from advancing flames.
• Architectural Features. Unenclosed balconies, decks, porches, or eaves on homes provide areas where sparks and embers can be trapped, smolder and ignite, rapidly spreading fire to the house. A high number of houses within a wildland-urban interface with these features implies a greater hazard to the community.

Defensible Space

Defensible Space accounts for sixteen percent of the total score in the risk/hazard assessment. Density and type of fuel around a home determines the potential fire exposure and the potential for damage to the home. A greater number of trees and shrubs and a greater volume of dry weeds and grass, woodpiles, and other combustible materials near the home will ignite more readily and produce more intense heat during a fire, increasing the threat of losing the home.

Suppression Capabilities

Suppression capabilities account for sixteen percent of the total assessment score. Knowledge of the capabilities or limitations of the fire suppression resources in a community can help county officials and residents take action to maximize the resources available. Factors considered in the assessment include:

• Availability, Quantity, and Training Level of Firefighting Personnel. When a fire begins in or near a community, having the appropriate firefighting personnel available to respond quickly is critical to saving structures. Whether there is a local paid fire department, volunteer department, or no local fire department impacts how long it takes for firefighting personnel to respond to a reported wildland fire or a threatened community.
• Quantity and Type of Fire Suppression Equipment. The quantity and type of available fire suppression equipment has an important role in minimizing the effect of a wildfire on a community. Effective wildland firefighting requires specialized equipment not commonly carried by urban firefighting forces.
• Water Resources. The availability of water resources is critical to fighting a wildland fire. Whether there is a community water system with adequate fire flow capabilities or whether firefighters must rely on local ponds or other drafting sites affects how difficult it will be for firefighters to protect the community.

Physical Conditions

Physical conditions account for 26 percent of the assessment. Fire behavior is influenced by physical conditions and is dynamic throughout the life of the fire. With the exception of changes to the fuel type and fuel density, the physical conditions in and around a community cannot be altered to make the community more fire safe. An understanding of how these physical conditions can influence the behavior of a fire is essential to planning effective preparedness activities, such as fuel reduction treatments. Physical conditions considered in the assessment include:

• Slope, Aspect, and Topography. In addition to local weather conditions, slope, aspect, and topographical variations can be used to predict fire behavior. West and south facing aspects are most prone to severe fire behavior due to preheated vegetation that has lower moisture content from daylong sun exposure. East aspect slopes in the Great Basin may experience afternoon downslope winds that may spread fire downhill. Steep slopes greatly influence fire behavior. Fire usually burns upslope with greater speed and longer flame lengths than on flat areas. Fire will burn downslope; however, it usually burns downhill at a slower rate and with shorter flame lengths than in upslope burns. Canyons, ravines, and saddles are topographical features that are prone to higher wind speeds than adjacent areas. Fires driven by winds grow at an accelerated rate compared to fires burning in non-windy conditions. Homes built mid-slope, at the crest of slopes or in saddles are most at risk due to wind-prone topography.
• Fuel Type and Density. Vegetation type, fuel moisture values, and fuel density around a community affect the potential fire behavior. Areas with thick, continuous, vegetative fuels carry a higher hazard rating than communities situated in areas of irrigated, sparse, or non-continuous fuels. Photos of representative fuel types are included in Appendix B.

2.3.3 Hazard Mapping

Initial wildfire hazard maps were generated using wildfire hazard delineations derived by the Nevada and Utah BLM from vegetation type data provided by the Nevada Gap Analysis Program dataset, which identifies vegetation types derived from satellite data. Land cover for the entire state was classified into one of 65 vegetation types at a resolution of thirty meters. The BLM fire specialist team reclassified the vegetation types into wildfire hazard potentials based on the hazard for that particular cover type. For example, pinyon-juniper cover types may be rated as extreme, while low sagebrush cover types are typically rated low. Hazard mapping was conducted for communities where high and extreme fuel types exist. No Churchill County communities had high or extreme fuel loading; therefore, hazard mapping was not conducted in the county.

2.3.4 Fire Behavior Worst-Case Scenario

The Project Team Fire Specialists described the worst-case scenarios included in this evaluation based on their analyses of the severe fire behavior that could occur given a set of weather conditions, observed fuel load conditions, and minimal fire suppression resources. Dry weather conditions, particularly successive years of drought in combination with steep slopes or high winds can create situations in which the worst-case fire severity scenario can occur. These scenarios describe a maximum potential for loss of property and, in some cases, human lives. The worst-case scenario does not describe the most likely outcome of a wildfire event in the interface, but it illustrates the potential for damage if a given set of conditions were to occur simultaneously. The worst-case scenarios are described in this document for public education purposes and are part of the basis for the fuel reduction recommendations.

2.4 Interviews with Fire Personnel

The RCI Project Teams interviewed local fire department personnel and local area Fire Management Officers to obtain information on wildfire training, emergency response time, personnel and equipment availability and capability, evacuation plans, pre-attack plans, and estimates of possible worst-case scenarios. Local fire personnel reviewed maps showing the history of wildfires to ensure that local information on wildland fires was included. Refer to Appendix C for a list of persons contacted.

2.5 Recommendation Development

A wide variety of treatments and alternative measures can be used to reduce ignition risks, mitigate fire hazards, and promote fire-safe communities. Proposed recommendations typically include physical removal or reduction of flammable vegetation, increased community awareness to the risk of fires and how to reduce that risk, and coordination among fire suppression agencies to optimize efforts and resources. The project team met repeatedly to analyze community risks and hazards, treatment alternatives, and treatment benefits. Treatment recommendations to reduce existing risks and hazards were formulated based upon professional experience, quantitative hazard assessment, and information developed in conjunction with the Living With Fire publications, National Fire Plan, and FIREWISE resources (National Fire Plan website; FIREWISE website; and Nevada Cooperative Extension publications.)